utils.tenor_sort_series
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spice.utils.tenor_sort_series(series: Series) -> Series

   Vectorized tenor sorting function for pandas DataFrame or series
   sort_values(key=).

   Parameters:
      **series** -- pandas Series of tenor strings (e.g., ["3M", "1Y",
      "5Y"])

   Returns:
      pandas Series of sort keys in months (e.g., [3, 12, 60])

   -[ Example ]-

   >>> df = pd.DataFrame({'tenor': ['5Y', '3M', '1Y'], 'yield': [0.05, 0.03, 0.04]})
   >>> df.sort_values('tenor', key=tenor_sort_series)
